Reversing switch for dynamo-electric machines



.1. H. BLANKENBUEHLER 2179.320

REVERSING SWITCH FOR DYNAMO-ELECTRIC MACHINES Nova '3', 1939.

Original Filed June 15, 1955 Sheets-Sheet l WITNESSES: 23

A TToR NEY Patented Nov. 7, 1939 STATS iersa'r REVERSING SWITCH FOR DYNAF/EQ-ELEC- 'llRHC MACHINES of Pennsylvania (Driginai application dune 15, 1935, Serial No.

26,872, new Patent No. 2,121,

31, dated dune 21, 1938. Divided and thi appiication June 16, 1937, Serial No. 143,454

5 Claims.

My invention relates, generally, to dynamoelectric machines and it has particular relation to load circuit reversing switches therefor.

This application is a division of my application Serial No. 26,872, filed June 15, 1935, now Patent No. 2,121,581, issued June 21, 1938.

In the construction of direct-current dynamoelectric machines, it is often desirable to provide for reversing the polarity of the output circuit. It is particularly desirable to provide for this reversal when the dynamo-electri machine is used as a generator to supply current for maintaining a welding arc. Under certain welding conditions it is preferable to apply one polarity to the welding electrode while under other conditions it is preferable to apply opposite polarity. In order to facilitate changing the polarity of the output circuit of the dynamo-electric machine, a reversing switchis provided for establishing the necessary connections.

Under normal operating conditions, the load circuit of the dynamoelectric machine will be open when the connections are changed to reverse the polarity. Such operating conditions occur when the dynamo-electric machine is employed for performing arc welding operations. It is, therefore, unnecessary to provide. a switch with high are rupturing capacity. Thus, a switch with substantially no arc rupturing capacity may be interposed directly between the output circuit of the dynamo-electric machine and its load terminals to which the load circuit is connected.

The object of my invention, generally stated, is to provide a reversing switch for a dynamoelectric machine which shall be simple and efiicient in operation, and which may be readily and economically manufactured and installed.

The principal object of my invention is to provide for reversing the connections between two pairs of conductors.

An important object of my invention is to provide for reversing the polarity applied by a directcurrent generator to its load terminals.

Another important object of my invention is to provide for mountin a reversing switch, interposed in the output circuit of a direct-current generator, inside of the frame of the generator.

Another object of my invention is to provide for mounting a reversing switch inside of the frame of a direct-current generator and for operating the switch from outside of the generator.

A further object of my invention is to provide for mounting a reversing switch for a direct-current generator inside of the generator on termii. mid-16) nals of the switch which project through the generator frame,

A still. further object of my invention is to provide a reversing switch comprising a pair of interconnected switch members and a common switch member for connection to one pair of conductors slide connected to another pair of conductors and disposed to engage either of the interconnected switch members and the common switch member.

Still another object of my invention is to provide a reversing switch comprising a pair of interconnected switch members and a common switch member for connection to one pair of conductors a slide connected to another pair of conductors disposed to engage either of the interconnected switch members and the common switch member and for mounting the reversing switch on its terminal members, one being connected to one of the pair of interconnected switch members and the other being connected to the common switch member.

Other objects of invention will, in part, be obvious and, in part, appear hereinafter.

My invention, accordingly, is disclosed in the embodiment hereof shown in the accompanying drawings, and comprises the features of construction, combination of elements, and arrangements of parts, which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope c invention reference may be had to the following detailed description taken in connection with the accompanying drawings, in which:

Figure l i a View, in side elevation, showing the generator and a portion of the motor of a motor-generator set in which a switch constructed in accordance with this invention may be incorporated;

Fig. 2 is a cross-sectional view showing the arrangement of the reversing switch inside of the generator illustrated in Fig. 1;

Fig. 3 illustrates diagrammatically the circuit connections between the output circuit of the generator and the load circuit;

Fig. l is a View, in side elevation, showing the of the reversing switch;

Fig. 5 is a view, in side elevation, showing he construction of the switch base;

Fig, 6 is a view in end elevation of the switch base shown in Fig. 5;

Fig. 7 is a bottom plan view of the switch base shown in Fig. 5;

Fig. 8 is a view, in side elevation, showing the construction of the slide;

Fig. 9 is a sectional view taken along the line IX-IX of Fig. 8;

Fig. 10 is a sectional view taken along the line XX of Fig. 8; and

Fig. 11 is a bottom plan view of the slide shown in Fig, 8.

Referring now particularly to Figs. 1 and 2 of the drawings, the reference character l5 designates, generally, the frame of a generator. The details of construction of the frame l5 are set forth in my copending application Serial No. 25,873, filed June 15, 1935, now Patent No. 2,0943%, issued Sept. 28, 1937, and assigned to the assignee of this application. The detailed construction of the generator is shown in my copending application Serial No. 26,871, also filed June 15, 1935, now Patent No. 2,125,062, issued July 26, 1938, and assigned to the assignee of this application. Since the details of the frame construction the construction of the generator form no part of this invention, only sufficient reference herein will be made thereto in order to illustrate the application of the reversing switch to the generator.

As illustrated in Fi 2 of the drawings, the frame is provided with inwardly projecting poles i8 and il, each of which is respectively provided with a series field winding I 3 and I9. Commutating field windings 2B and 2! are also provided. An armature 22-2 is positioned between the poles i6 and il and is provided with main brushes 2.'i23 and auxiliary brushes E l-24, the latter being short-circuited since the generator illustrated herein is of the cross-field type.

In order to reverse the polarity of the output circuit of the generator, a reversing switch, shown generally at 25, is provided. As illustrated, the reversing switch 25 is mounted inside of the frame l5 and is arranged to be operated by means of a lever which is rotatably mounted in the frame I5 and is provided at its outer end with a handle 21, that may be readily gripped by the operator to change the position of the switch 25, as may be desired.

In order to clearly point out the connections to the reversing switch 25, the output circuit of the generator will be traced in detail as follows, beginm'ng at the reversing switch 225. The circuit extends through the conductor 28, series field winding i8, conductor 29, commutating field winding 2%, conductor til, brush 23, armature 22, brush 23, conductor 36, commutating field winding 28, conductor 32, series field winding 59, and conductor 33 back to the reversing switch 25.

As shown in Fig. 3, the conductors 28 and from the output circuit of the generator, are connected to contact bars 36 and 3?, respectively, which form a part of a slide shown generally at 38. In the position shown, the contact bars 38 and 31 are disposed to engage an outside switch member 39 and a center or common switch member Mi, respectively. The slide 38 may be moved so that the contact bars 36 and 37 engage, respectively, the common switch member l-t and another outer switch member 4! The outer switch members 39 and ii may be interconnected by means of a conductor 42.

The load circuit comprising conductors i3 and 4 3 is connected respectively to the common switch member in and the outer switch member 4!. In effect, due to the interconnecting conductor 42,

the conductor 44 is also connected to the other outer switch member 39. The conductors :3 and 44 are connected, respectively, to a welding electrode 45 and work 46 between which an arm. ii may be maintained.

While the output circuit has been illustrated as being connected to the contact bars 35 and and the load circuit as being connected to the switch members 40 and 4!, it will be observed that this arrangement of connections may be reversed and that the load circuit may be connected to the contact bars 35 and 31 and the output circuit may be connected to the switch members iii and M as may be desired. However, for purposes which will appear hereinafter, it is preferable to connect the load circuit to the stationary switch members 49 and 4|.

Referring now particularly to Figs. 5, 6 and '7 of the drawings, it will be observed that the switch members 39, 48 and i! are mounted on a rectangular switch base 5i comprising a flat plate of insulating material. Each of the outer switch members 39 and ll comprises jaws 52 and 53 which may be spaced apart by means of spacers 56. A flat headed bolt 55 is provided for mounting the outer switch member 39 in assembled relation.

The common switch member 40 comprises jaws 56 and 5'1, which extend oppositely and in the directions of the outer switch members 3.) and 4 l. The jaws 56 and 51 are spaced apart by means of a spacer 58, which comprises a flat bar that also serves as a stop for the movement of the contact bars 36 and 37 of the slide 38.

In order to provide for connection to the load circuit comprising the conductors 43 and M. ter minal studs 59 and Eiil are provided individually, respectively, to the outer switch member 4! and the common switch member 40. Wing nuts 6! and 62, respectively, are provided for securing terminals 53 and 64, Fig. 1, in proper contact engagement with the studs 59 and 60.

As is illustrated more clearly in Fig. 2 of the drawings, the switch 25 is arranged to be mounted inside of the frame IS on its own terminals 55 and 65. It is, therefore, unnecessary to provide additional mounting means for supporting the switch 25. The terminal studs 59 and iii] project through suitable openings in the frame l5 and are insulated therefrom by means of insulating sleeves 65 which surround the terminal studs 59 and 60 and which are provided with reduced sections that project through the frame l5. Additional insulating washers 66 are provided outside of the frame for cooperation with the insulating sleeves 65 to provide for completely insulating the studs 59 and 60 from the frame i5. Metallic washers 6'! are provided outside of the insulating washers 66, the assemblies being held in position by means of lock nuts 68. As shown, the terminal 64 may be positioned between the lock nut 68 and the wing nut 62.

As illustrated in Fig. '7 of the drawings, terminals H and 12 are provided, respectively, on the outer switch members 4| and 39 for connection by means of the interconnecting conductor 42. It will be understood, however, that a flat copper bar or strap may be provided for interconnecting the outer contact members 39 and 4| instead of the conductor and terminal arrangement as illustrated.

Referring now particularly to Figs. 8 through 11 of the drawings, it will be observed that the slide 38 is there shown in detail. The contact bars 36 and 31 are mounted on insulating spacing strips iii and it by means of flat headed screws ill. Terminals l8 and l9 are provided for the contact bars 8'5 and 55, respectively, for connection to conductors and 23, respectively, ing the load terminals of the generator.

In order to operate the slide 38, a guide is provided having a slotted opening therein, The inner end of the operating lever is arranged to project into the slotted opening and on rotation thereof. is arranged to move a slide from one position to another. For ample, in the arrangement shown in l of idrawings, the slide 33 is so positioned that contact bars 35 and 3'3 are in ngagemet, spectively, with the outer switch member the common switch member When the sl de 38 is moved to the left, the contact bars and iii will en age, respectively, the com switch member ill and the outer switch member as is shown by the dot and dash outline of the slider d in the left-hand position in Fig. 4. ihe guide lid is spaced from the insulating strips l5 and by means of fiber spacers and is secured thereto by means of flat headed screws t will now be observed that the reversing switch 25, as shown in assembled form in Fig. i of the drawings, comprises outer switch members having spaced apart jaws and 5B and that the Contact bars 3% and it'l of the slide 3 3 are arranged to engage either of the outer switch members, depending upon the position of the slide. Also depending upon the position of the slide one or the other of the contact bars and 3? will engage the spaced apart jaws and ill of the common or inner switch member lil. Because of this arrangement, the distance be tween the center lines of the contact bars and Si is substantially equal to the distance between either of the center lines of the out r switch members 3% or ii and the center line of the inner or common switch member M. With this arrangement, a minimum of parts required to provide the necessary reversing connections be-- tween the conductors 28- 53 and the conductors ittd. Furthermore, in View of the fact that the reversing switch 2'5 is mounted on the studs 5% and. which form the output terminals of the generator, the design is simplified and the expense of construction is reduced.

Since certain further changes may be made in the foregoing construction different embodiments or the invention may be made without departing from the scope thereof, it. intended that all matter shown in the accompanying drar ings, or set forth in the above descri, tion shall be interpreted as illustrative and not in a limit-- ing sense.

I claim as my invention:

1. A switch for reversing the ccnnbtions of a pair conductors to another pair of cond 'ctors comprising, in combination, a m iber formed of a flat plate of insulating mate a pair of switch members posit oned at oppo ite ends of said base member, circuit means terconnecting said switch members, a common midway between said first-mentioned members, a of terminal members to support ba member to be con to one of pairs of conductors, one oi terminals being connected to one of said firstmentioned switch members the other being connected to common s" itch member, and a pair of sliolable switch members connected to said other pair of conductors, said slidable switch of sa d base member, circuit means interco necting switch members, a common ch positioned on base member midway betteen d first-mentioned switch members, a pair of terminal members disposed to support said base member and to be connected to one or said pairs of conductors, one of said terminals being connected to one of said firstmentioned switch members and the other being connected to said common switch member, a slide comprising a pair of contact bars spaced apart in fixed relation by and secured to a pair of insulating spacing strips, said contact bars being disposed to be connected to said other pair of conductors and to engage either of said firstmentioned switch members and said common switch member, and means for operating said slide to reverse the connections between said pairs of conductors.

3. A switch for reversing the connections of a pair of conductors to another pair of conductors comprising, in combination, a base member formed of a flat plate of insulating material, a pair of switch members positioned at opposite ends of said base member, circuit means interconnecting said switch members, a common switch member positioned on said base member midway between said first-mentioned switch members, a pair or terminal members disposed to support said base member and to be connected to one of said pairs of conductors, one of said terminals being connected to one of said firstmentioned switch members and the other bein connected to said common switch member, a rigid slide member comprising a pair of contact bars secured to a pair of insulating strips and spaced apart at a distance substantially equal to the distance between said common switch mem her and one of said first-mentioned switch members, said contact bars being connected to said other pair of conductors and disposed to engage either of said first-mentioned switch members and said common switch member, and a handle operatively connected to said slide for moving it to reverse the connections between said pairs of conductors.

i. A switch for reversing the connections of a pair of conductors to another pair of conductors comprising, in combination, a base member formed of a ilat plate of insulating material, a pair of spaced apart switch jaws positioned at each end of said base member, circuit means interconnecting said pairs of switch jaws, a common pair of spaced apart sit "itch jaws positioned on said base member midway between said pairs of switch jaws and aligned therewith, a pair of terminal members disposed to support said base member and to be connected to one of said pairs of conductors, one of said terminals being secured to one of said pairs of switch jaws and the other being secured to said common switch jaws, a rigid slide member comprisin a pair of contact bars spaced apart by and secured to a pair of insulating strips, said contact bars being disposed to be connected to said other pair of conductors and to engage either of said pairs of switch jaws and said common switch jaws, means associated with the common switch jaws securing the slide members in association with the base member, and means for operating said slide to reverse the connections between said pairs of conductors.

5. A switch for reversing the connections of one pair of conductors to another pair of conductors comprising, in combination, a base member formed of a flat plate of insulating material, a pair of spaced apart switch jaws positioned at each end of said base member, circuit means interconnecting said pairs of switch jaws, a com mon pair of spaced apart switch jaws positioned on said base member midway between said pairs of switch jaws and aligned therewith, a pair of terminal members disposed to support said base member and to be connected to one of said pairs of conductors, one of said terminals being secured to one of said pairs of switch jaws and the other being secured to said common switch jaws, a slide comprising a pair of contact bars secured in fixed relation by a pair of insulating strips and spaced apart at a distance substantially equal to the distance between said common switch jaws and one of said pairs of switch jaws, said contact bars being connected to said other pair of conductors and disposed to engage either of said pairs of switch jaws and said common switch jaws, means associated with the common switch jaws movably securing the slide to the base member, a guide member secured to said slide, and a handle operatively disposed to said guide member I01 moving said slide to reverse the connections between said pairs of conductors.

JOHN H. BLANKENEUEHLER. 

